// Copyright 2018 The go-ethereum Authors
// This file is part of the go-ethereum library.
//
// The go-ethereum library is free software: you can redistribute it and/or modify
// it under the terms of the GNU Lesser General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// The go-ethereum library is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU Lesser General Public License for more details.
//
// You should have received a copy of the GNU Lesser General Public License
// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.

package core

//
//// senderCacher is a concurrent tranaction sender recoverer anc cacher.
//var senderCacher = newTxSenderCacher(runtime.NumCPU())
//
//// txSenderCacherRequest is a request for recovering transaction senders with a
//// specific signature scheme and caching it into the transactions themselves.
////
//// The inc field defines the number of transactions to skip after each recovery,
//// which is used to feed the same underlying input array to different threads but
//// ensure they process the early transactions fast.
//type txSenderCacherRequest struct {
//	txs    []*types.Transaction
//	inc    int
//}
//
//// txSenderCacher is a helper structure to concurrently ecrecover transaction
//// senders from digital signatures on background threads.
////type txSenderCacher struct {
////	threads int
////	tasks   chan *txSenderCacherRequest
////}
//
//// newTxSenderCacher creates a new transaction sender background cacher and starts
//// as many procesing goroutines as allowed by the GOMAXPROCS on construction.
//func newTxSenderCacher(threads int) *txSenderCacher {
//	cacher := &txSenderCacher{
//		tasks:   make(chan *txSenderCacherRequest, threads),
//		threads: threads,
//	}
//	for i := 0; i < threads; i++ {
//		go cacher.cache()
//	}
//	return cacher
//}
//
//// cache is an infinite loop, caching transaction senders from various forms of
//// data structures.
//func (cacher *txSenderCacher) cache() {
//	for task := range cacher.tasks {
//		for i := 0; i < len(task.txs); i += task.inc {
//			//types.Sender(task.abi, task.txs[i])
//		}
//	}
//}
//
//// recover recovers the senders from a batch of transactions and caches them
//// back into the same data structures. There is no validation being done, nor
//// any reaction to invalid signatures. That is up to calling code later.
//func (cacher *txSenderCacher) recover(txs []*types.Transaction) {
//	// If there's nothing to recover, abort
//	if len(txs) == 0 {
//		return
//	}
//	// Ensure we have meaningful task sizes and schedule the recoveries
//	tasks := cacher.threads
//	if len(txs) < tasks*4 {
//		tasks = (len(txs) + 3) / 4
//	}
//	for i := 0; i < tasks; i++ {
//		cacher.tasks <- &txSenderCacherRequest{
//			txs:    txs[i:],
//			inc:    tasks,
//		}
//	}
//}
//
//// recoverFromBlocks recovers the senders from a batch of blocks and caches them
//// back into the same data structures. There is no validation being done, nor
//// any reaction to invalid signatures. That is up to calling code later.
//func (cacher *txSenderCacher) recoverFromBlocks(blocks []*types.Block) {
//	count := 0
//	for _, block := range blocks {
//		count += len(block.Transactions())
//	}
//	txs := make([]*types.Transaction, 0, count)
//	for _, block := range blocks {
//		txs = append(txs, block.Transactions()...)
//	}
//	cacher.recover(txs)
//}
